Sunday, August 29, 2010

Astronaut conditioning research

It turns out that maintaining the strength of muscle and bone is really important.....and is also a real challenge when weights are weightless.

In terms of High Intensity Interval Training (HIIT) there are a few interesting ideas being tried out:

Short bursts of high-intensity resistance training, at around 70 per cent of the muscles' maximum capacity for 15 minutes, twice a day, should help, says Fitts. A range of studies in animals and volunteers confined to bed rest suggest this will protect muscles better than long periods of low-intensity aerobic exercise. It may also guard against bone loss. Dan Bikle of the University of California, San Francisco, who has studied bone loss in rats whose hindquarters are suspended off the ground, recommends intense weight-bearing exercise for 1 second in 10, for a few minutes each day

Scientists found that the only way they could reverse this process was by using exercises that deformed the bone cells (think of them squishing, like a tennis ball you’re standing on). This, they found, slowed bone mineral reabsorption (a natural process in the body that weakens bones) and increased bone density. They thought the iRED would accomplish this. But it didn’t work.“The elastic bands simply didn’t provide enough resistance,” says Garcia. “And the resistance they did provide wasn’t consistent enough to affect the bone mass of the astronauts.”

Rule 1: Use heavy weights (at least 80 percent of your max).“In order to sufficiently work muscle and bone fiber to the point where the aging process is slowed,” says Spiering, “people can’t just run and play sports.” In space, the NASA astronauts experienced accelerated atrophy — even if they ran on treadmills. Heavy lifting — rather than static loading, as during a jog — was the only way, NASA scientists found, to deform the bone cells enough to grow cortical bone. To achieve this effect on Earth, Spiering found that resistance training — exercises such as squats, bench presses, and dead lifts — at 80 to 85 percent of the maximum amount you can lift is the optimum way to stop bone and muscle deterioration.

Rule 2: Slow down. Lifting weights isn’t nearly as critical as how you lower them.The iRED revealed that the fluctuating resistance due to its elastic webbing limited eccentric forces — the resistance generated by lowering a weight — by 60 percent. Although iRED users were able to gain some muscle strength from the machine, their bone density decreased rapidly. Schneider assumed that the machine’s inability to generate eccentric force was the culprit. So in 2003 she put a group of men on a steady diet of exercises with free weights, which increase eccentric force when lowered slowly. (This theory had been out there before. In the early 2000s, many fitness buffs began clinging to an exercise program called Super Slow, which promised to increase metabolism and lower bad cholesterol. It seemed to work — though people weren’t sure why — and soon after many people replaced it with more functional training like CrossFit.) After 16 weeks, she tested the men’s bone mineral density and found that it had improved dramatically from their pre-program levels.

Rule 3: Drop the number of reps (keep the intensity high).Earlier this year Scott Trappe, the director of the Human Performance Lab at Ball State University, in Muncie, Indiana, used NASA’s data from nine astronauts aboard the ISS to conduct and publish a study about weightlessness and exercise in the Journal of Applied Physiology. Using MRIs and biopsies to measure muscle fibers, he concluded that intense movements, like sprinting, jumping, and throwing (see the exercises at right), along with lifting heavy weights, resulted in better muscle size, a key element to protecting bones and thus keeping them from aging too quickly. The discovery wasn’t exactly surprising, but Trappe’s study did bust one misconception about the amount people exercise. “Most people think that more is better,” he says. “But our study showed that exercise should be done much less frequently than conventional wisdom suggests — but with much greater intensity.” Says Garcia: “The most recent space flight research indicates that doing six to eight reps — not the typical 10 — best maintains muscle function and strength.” In a recent study, Trappe found that elderly men who had been training three days a week, at 80 percent of their maximum loads, were able to maintain their muscle mass with just one high-intensity workout a week.

I don't know where I am going with this, but it is an interesting bunch of stuff to read. Train hard, less frequently, with slow negatives using heavy weights. Arthur Jones, John Little and Doug McGuff would be proud of NASA!

11 comments:

I am actually quite frustrated with NASA. The rig-ups they have to try to accomplish resistance training on a space station are quite silly. I have called and left messages multiple times with this Dr. Garcia trying to get him in touch with Randy Rindfleisch who makes the motorized Cra-Z-train equipment that many have seen me tortured with on youtube. This would be ideal for use on a space station as it is not gravity dependent in any way.

I have left about a half-dozen messages and even tried to contact them through their own phone system when The family and I were on a NASA tour...all to no avail.

I tried to drop into their laps a solution to a problem they are spending millions of taxpayer dollars on and they would not return a call. I finally just gave up.

I think that generalizing from the finding that 80 year old men are able to maintain muscle mass with one intense session a week as well as three implies that this optimal in different populations with different goals(gaining muscle size, increasing strength etc) is not tenable.

er, that would be "elderly" men training at 80% of max, not 80 year old men. Hard to say what "elderly" is exactly without seeing the study. It is possible to postulate that they were in fact overtraining in their 3 day per week regimen which allowed them to maintain muscle mass with just one day.

Doug seems to do decent on a once a week protocol. If one were to exercise with heavy elastic bands or similar elastic equipment with high enough resistance to cause failure within reasonable rep count (or TUT), I can't see why the result should be much different compared to free weights or machine exercises. Andreas

With a couple of parents who are entering the "golden years" while continuing to exercise regularly, I am very interested in the idea of 'old' people lifting heavy weights.

I have read about the rejuvenating hormonal benefits of heavy lifts, but has anyone heard of studies that have 60+ year old people lifting weights near 80% of 1RM?

Looking at the programs that my parents' personal trainer provides, there is a lot of functional/core stability/machine work, but not any heavy lifting.

Obviously a person looking to begin lifting heavy after a lifetime of injuries, posture imbalances and other issues would probably need some serious remedial training, but it seems like the benefits could prove to be worth the effort.

This study and McGuff's commentary seem to be geared towards using weight machines instead of free weights.

Do you know if there have there been any studies done regarding older people performing lifts like the deadlift and squat?

I am curious about the supposed hormonal response that heavy, demanding lifts like these can elicit. It seems like stimulating natural androgen release could only help an older person to maintain their health.

ha a look at the post I've just put up here - resistance training to create an anabolic state is very important to those losing muscle.

As to deadlifts and squats, I don't see a problem as long as the form is good. Unfortunately often it isn't and it is easy to hurt yourself with those lifts. I think deadlifts and squats are movements that everyone should do, but not necessarily exercises that everyone should do if you see the difference.